Modelling the impact of microbial loop on aquatic food webs

Abstract: In order to control algal blooms, it is necessary to better understand microbial interactions in aquatic ecosystems. Based on the traditional ‘Nutrients-Phytoplankton-Zooplankton-Detritus’ (NPZD) model, the ‘Nutrients-Phytoplankton-Zooplankton-Detritus+Bacteria’ (NPZD+B) model has been developed to investigate the impact of the microbial loop on aquatic food webs via nutrient cycling processes. The results of the NPZD+B model showed the positive impact of the microbial loop on phytoplankton growth, and illustrated the importance of ‘bottom-up’ (resource) control of algal blooms in aquatic ecosystems. The study concludes that the microbial loop is an important model component for simulating water quality dynamics when nutrients are limited in water bodies. The NPZD+B model provides an improved mechanistic understanding of bacteria-phytoplankton interactions in aquatic ecosystems.